The solvent extractable organic compounds （SEOC）, including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, and dicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured ...The solvent extractable organic compounds （SEOC）, including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, and dicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured via gas chromatography-mass spectrometry for determining the characteristics and sources of these organic pollutants. The concentrations of total n-alkanes, PAHs, and organic acids before Chinese Spring Festival Eve （1025.5, 95.9, and 543.3 ng/m3, respectively） were higher than those after （536.6, 58.9, and 331.8 ng/m3, respectively）, n-Aalkanes and PAHs had much higher concentration in nighttime than those in daytime because of high relative humidity and low wind speed during the night. Combustion of coal and exhaust emission were major sources of n- alkanes. It could be concluded by the characteristic ratios that the primary source of PAHs in fine particles was the combustion of coal, but the combustion of gasoline was in the next place. The ratios of C18：0/C16 indicated the contribution of vehicular emissions to the fatty acids. Dicarboxylic and aromatic acids were abundant in daytime than in nighttime because these acids were secondary organic acid and the photochemical degradation of aromatic hydrocarbons was the main source.展开更多
THE Spring Festival,or Chinese New Year,is the most prominent and celebrated festival among Chinese people.Its history can be traced back thousands of years.The holiday begins on the first day of Chinese lunar calenda...THE Spring Festival,or Chinese New Year,is the most prominent and celebrated festival among Chinese people.Its history can be traced back thousands of years.The holiday begins on the first day of Chinese lunar calendar and ends on the 15th day of the same lunar month,which is celebrated as the Lantern Festival.In 2019,the first day of the Lunar New Year falls on February 5.The holiday is filled with buoyancy and happiness as people take part in an array of celebrations,one of the most important occasions of which is family reunion.展开更多
Tang-suits, traditional Chinese clothing, always inadvertently reveal a sort of classical flavor that let us enjoy tasting the strong oriental charm to our hearts’ content thanks to
China is a big, great country with a long history. There are many traditional festivals in our country, but my favorite traditional festival is the Spring Festival. It is a very important festival in Chinese culture.D...China is a big, great country with a long history. There are many traditional festivals in our country, but my favorite traditional festival is the Spring Festival. It is a very important festival in Chinese culture.During the Spring Festival, everyone returns home for a family reunion. We can have a big feast.展开更多
Tasting delicious local food and watching an NBA basketball game live enabled me to gain a deeper insight into Phoenix,an international sister city of Chengdu.On the second day after the Chinese New Year holiday,I lef...Tasting delicious local food and watching an NBA basketball game live enabled me to gain a deeper insight into Phoenix,an international sister city of Chengdu.On the second day after the Chinese New Year holiday,I left Chengdu on an official trip to the United States as a staff member of the Chengdu Foreign and Overseas Chinese Affairs Office.After a flight of 20 hours,we ar-展开更多
基金supported by the National Basic Re-search Program (973) of China (No. 2007CB407303)the National Natural Science Foundation of China (No.40525016)the Hi-Tech Research and Development Program (863) of China (No. 2006AA06A301).
文摘The solvent extractable organic compounds （SEOC）, including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, and dicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured via gas chromatography-mass spectrometry for determining the characteristics and sources of these organic pollutants. The concentrations of total n-alkanes, PAHs, and organic acids before Chinese Spring Festival Eve （1025.5, 95.9, and 543.3 ng/m3, respectively） were higher than those after （536.6, 58.9, and 331.8 ng/m3, respectively）, n-Aalkanes and PAHs had much higher concentration in nighttime than those in daytime because of high relative humidity and low wind speed during the night. Combustion of coal and exhaust emission were major sources of n- alkanes. It could be concluded by the characteristic ratios that the primary source of PAHs in fine particles was the combustion of coal, but the combustion of gasoline was in the next place. The ratios of C18：0/C16 indicated the contribution of vehicular emissions to the fatty acids. Dicarboxylic and aromatic acids were abundant in daytime than in nighttime because these acids were secondary organic acid and the photochemical degradation of aromatic hydrocarbons was the main source.
文摘THE Spring Festival,or Chinese New Year,is the most prominent and celebrated festival among Chinese people.Its history can be traced back thousands of years.The holiday begins on the first day of Chinese lunar calendar and ends on the 15th day of the same lunar month,which is celebrated as the Lantern Festival.In 2019,the first day of the Lunar New Year falls on February 5.The holiday is filled with buoyancy and happiness as people take part in an array of celebrations,one of the most important occasions of which is family reunion.
文摘Tang-suits, traditional Chinese clothing, always inadvertently reveal a sort of classical flavor that let us enjoy tasting the strong oriental charm to our hearts’ content thanks to
文摘China is a big, great country with a long history. There are many traditional festivals in our country, but my favorite traditional festival is the Spring Festival. It is a very important festival in Chinese culture.During the Spring Festival, everyone returns home for a family reunion. We can have a big feast.
文摘Tasting delicious local food and watching an NBA basketball game live enabled me to gain a deeper insight into Phoenix,an international sister city of Chengdu.On the second day after the Chinese New Year holiday,I left Chengdu on an official trip to the United States as a staff member of the Chengdu Foreign and Overseas Chinese Affairs Office.After a flight of 20 hours,we ar-
